Herbicidal 4-trifluoromethyl-4&#39;nitrodiphenyl ethers

ABSTRACT

Compounds of the formula ##STR1## wherein X is a hydrogen atom, a halogen atom, a trihalomethyl group, an alkyl group, or a cyano group, 
     Y is a hydrogen atom, a halogen atom, or a trihalomethyl group, and 
     Z is a hydroxy group, an alkoxy group, and alkyl group, a halogen atom, an amino group, an alkylthio group, a cyano group, a carboxy group, a carbalkoxy group, a carboxyalkyl group, a carbalkoxyalkyl group, an alkanoyloxy group, or a carbamoyloxy group, 
     And compositions containing these compounds exhibit herbicidal activity.

This is a division of application Ser. No. 331,719, filed Feb. 12, 1973,now U.S. Pat. No. 3,928,416, which is in turn a continuation-in-part ofapplication Ser. No. 234,651, filed Mar. 14, 1972; now U.S. Pat No.3,798,276, granted Mar. 19, 1974.

This invention relates to novel compounds which show activity asherbicides, to novel herbicidal compositions which contain thesecompounds, and to new methods of controlling weeds with these herbicidalcompositions.

Certain diphenyl ethers have been shown to be effective weed controlagents. However, the herbicidal effectiveness of a given diphenyl ethercannot be predicted from an examination of the substituent groupsattached to the phenyl rings in the ether, and often quite closelyrelated compounds will have quite different weed control abilities.Various diphenyl ethers may have overlapping or complementary areas ofactivity or selectivity, and can thus be useful in combination tocontrol a variety of weeds upon application of a single composition.Furthermore, the diphenyl ethers heretofore disclosed as herbicides arenot completely effective. An ideal herbicide should give selective weedcontrol, over the full growing season, with a single administration atlow rates of application. It should be able to control all common weedsby killing them as the seed, the germinating seed, the seedling, and thegrowing plant. At the same time, the herbicide should not be phytotoxicto the crops to which it is applied and should decompose or otherwise bedissipated so as not to poison the soil permanently. The known diphenylether herbicides fall short of these ideals, and it would thus bedesirable to have new herbicides which show even more selective controlof undesirable plants among desirable crop plants or which complementthe known diphenyl ethers in activity.

In accordance with the present invention, there is provided a new classof novel diphenyl ethers having the formula ##STR2## wherein X is ahydrogen atom, a halogen atom, preferably a fluorine atom or a chlorineatom, a trihalomethyl group, preferably a trifluoromethyl group, a (C₁-C₄) alkyl group, preferably a methyl group, or a cyano group,

Y is a hydrogen atom, a halogen atom, preferably a fluorine atom or achlorine atom, or a trihalomethyl group, preferably a trifluoromethylgroup, and

Z is a hydroxy group, an alkoxy group, preferably having 1 to 6 carbonatoms, and most preferably 1 to 4 carbon atoms, an alkyl group,preferably having 1 to 4 carbon atoms, a halogen atom, preferably achlorine atom or a fluorine atom, an amino group, preferaby having up to6 carbon atoms, an alkylthio group, preferably having 1 to 4 carbonatoms, a cyano group, a carboxy group, a carbalkoxy group, --CO₂ R,preferably having 1 to 4 carbon atoms in the alkoxy moiety, acarboxyalkyl group, --R'CO₂ H, preferably having up to 4 carbon atoms, acarbalkoxyalkyl group, --R'CO₂ R, preferably having up to 6 carbonatoms, an alkanoyloxy group, --OCOR, preferably having up to 4 carbonatoms, optionally substituted with a halogen atom, or a carbamoyloxygroup, --OCONH₂, --OCONHR, or --OCONR₂, preferably having up to 6 carbonatoms.

In the above definitions of the Z substitutent, R represents an alkylgroup, and R' represents a divalent alkylene group. The alkyl oralkylene portion of the alkyl-containing X and Z substituents can haveeiher a straight- or branched-chain or a cyclic spatial configuration.

As used in the present specification and claims, the term "alkoxy group"is intended to include both unsubstituted alkoxy groups as well assubstituted alkoxy groups which have one or more of the hydrogen atomsreplaced by a substituent group. Among the substituted alkoxy groupswhich Z can represent are alkoxy groups of preferably up to 4 carbonatoms substituted with a halogen atom, a hydroxy group, a (C₁ -C₄)alkoxy group, a carboxy group, a carbalkoxy group, preferably having upto 4 carbon atoms in the ester alkoxy group, a trihaloalkyl group,preferably a trifluoromethyl group, an alkenyl group, an alkynyl group,preferably an ethynyl group, an amino group, an alkyl-or dialkylaminogroup, including heterocyclic substituents such as morpholino,piperazino, piperidino, and the like, and preferably having a total ofup to 4 carbon atoms, an alkylthio group, preferably having up to 4carbon atoms, a alkylsulfonyl group, preferably having up to 4 carbonatoms, an epoxy group, an alkylcarbonyl group, includinghalo-substituted alkylcarbonyl, and preferably having up to 4 carbonatoms in the alkyl group, most preferably methylcarbonyl, a carbamoylgroup, including alkyl- or dialkylcarbamoyl, preferably having a totalof up to 4 carbon atoms in the alkyl substituents.

The term "amino group" as used in the present specification and claimsis intended to include an unsubstituted amino group, --NH₂, as well asamino groups having one or both hydrogen atoms replaced by substituentgroups. Among the substituted amino groups which Z can represent areamino groups substituted with one or two alkyl groups, preferably havinga total of up to 6 carbon atoms, halo-, hydroxy-, or alkoxy-substitutedalkyl groups, preferably having a total of up to 6 carbon atoms, one ortwo alkylthio carbonyl groups, preferably having a total of up to 4carbon atoms in the alkyl moiety, carboxy groups, carbalkoxy groups,preferably having up to 4 carbon atoms in the alkoxy group, carbamoylgroups, including alkyl or dialkylcarbamoyl groups, preferably having upto 4 carbon atoms in the alkyl moiety, alkylcarbonyl groups, preferablyhaving up to 4 carbon atoms, or halo-substituted alkylcarbonyl groups,preferably having up to 4 carbon atoms.

The substituted amino groups can also be heterocyclic amino groups, suchas piperidino, piperazino, morpholino, pyrrolidinyl, and the like. Whenthe Z substituent is or contains a carboxy group, either the free acidor the salt form can be used.

When Z is an alkyl group, it may be optionally substituted with ahydroxy group, a (C₁ -C₄)alkoxy group, or a halogen atom, preferably achlorine atom.

These novel compounds have been found to show unexpected activity asweed control agents. In a preferred embodiment of the invention, X is ahalogen atoms or a cyano group, Y is a hydrogen atom or a halogen atom,and Z is an alkoxy group.

Examples of the compounds of the invention embraced by Formula Iinclude:

2-chloro-α,α,α-trifluoro-p-tolyl-4-nitro-m-tolyl ether,

2-bromo-α,α,α-trifluoro-p-tolyl-3-butyl-4-nitrophenyl ether,

2,α,α,α-tetrafluoro-p-tolyl-4-nitro-3-n-propoxyphenyl ether,

2-chloro-6,α,α,α-tetrafluoro-p-tolyl-3-methylthio-4-nitrophenyl ether,

2-chloro-α,α,α-trifluoro-p-tolyl-3-propyl-4-nitrophenyl ether,

2-chloro,-α,α,α-trifluoro-p-tolyl-3-ethoxy-4-nitrodiphenyl ether,

α,α,α-trifluoro-2-iodo-p-tolyl-3-ethoxy-4-nitrophenyl ether,

2,6-dichloro-α,α,α-trifluoro-p-tolyl-4-nitro-3-n-propoxyphenyl ether,

α,α, α,α',α',α'-hexafluoro-2,4-xylyl-3-n-butoxy-4-nitrophenyl ether,

2-cyano-α,α,α-trifluoro-p-tolyl-3-ethoxy-4-nitrophenyl ether,

2-chloro-6-cyano-α,α,α-trifluoro-p-tolyl-4-nitro-3-n-propoxyphenylether,

2-cyano-α,α,α-trifluoro-p-tolyl-3-carboxy-4-nitrophenyl ether,

2,6-dibromo-α,α,α-trifluoro-p-tolyl-3-methoxymethoxy-4-nitrophenylether,

2-chloro-α,α,α-trifluoro-p-tolyl-3-(2-hydroxyethoxy)-4-nitrophenylether,

2-α,α,α-tetrafluoro-p-tolyl-4-nitro-3-n-propylaminophenyl ether,

2-chloro-α,α, α-trifluoro-p-tolyl-3-dimethylamino-4-nitrophenyl ether,

2-cyano-α,α,α-trifluoro-p-tolyl-3-carbethoxy-4-nitrophenyl ether

2,6-dichloro-α,α,α-trifluoro-p-tolyl-3-carbethoxy-4-nitrophenyl ether

2-ethyl-α,α,α-trifluoro-p-tolyl-3-(2-carboxy ethoxy)-4-nitrophenylether,

α,α,α,α', α',α'-hexafluoro-2,4-xylyl-3-carbethoxymethyl-4-nitrophenylether, 2-cyano-α,α,α-trifluoro-p-tolyl-3-(2-carboxy propyl)-4-nitrophenyl ether,

2,α,α,α-tetrafluoro-p-tolyl-3-carbethoxymethoxy-4-nitrophenyl ether,

2-chloro-α,α,α-trifluoro-p-tolyl-3-(3,3-diethylureido)-4-nitrophenylether,2-chloro-6-cyano-α,α,α-trifluoro-p-tolyl-3-acetamido-4-nitrophenylether,

2-chloro-α,α,α-trifluoro-p-tolyl-3-carbethoxyamino-4-nitrophenyl ether,

2-chloro-α,α,α-trifluoro,-p-tolyl-3-chloro-4-nitrophenyl ether,

2-chloro-α,α,α-trifluoro-p-tolyl-3-hydroxy-4-nitrophenyl ether,

2-bromo-α,α,α-trifluoro-p-tolyl-3-butynyloxy-4-nitrophenyl ether

2-cyano-α,α,α-trifluoro-p-tolyl-3-(2-methyl)propynyloxy-4-nitrophenylether,

2,6-dichloro-α,α,α-trifluoro-p-tolyl-3-(2,2,2-trifluoro)-ethoxy-4-nitrophenylether,

2-chloro-α,α,α-trifluoro-p-tolyl-3-(2-dimethylaminoethoxy)-4-nitrophenylether,

2-bromo-α,α,α-trifluoro-p-tolyl-3-acetoxy-4-nitrophenyl ether,

α, α, α, α', α',α'-hexafluoro-2,4-xylyl-3-(2-hydroxyethylamino)-4-nitrophenyl ether

α⁴, α⁴, α⁴ -trifluoro-2,4-xylyl-3-amino-4-nitrophenyl ether,

2-chloro-α,α,α-trifluoro-p-tolyl-3-morpholino-4-nitrophenyl ether,

2-cyano-α,α,α-trifluoro-p-tolyl-3-(N-methylcarbamoyloxy)-4-nitrophenylether,

2-chloro-6,α,α,α-tetrafluoro-p-tolyl-3-propionamido-4-nitrophenyl ether,

2-chloro-α,α,α-trifluoro-p-tolyl-3-chloroacetamido-4-nitrophenyl ether,

α⁴, α⁴, α⁴ -trifluoro-2,4-xylyl-3-(2,3-epoxypropoxy)-4-nitrophenylether,

2-chloro-α,α,α-trifluoro-p-tolyl-3-(2,3-dihydroxypropoxy)-4-nitrophenylether,

2-cyano-α,α,α-trifluoro-p-tolyl-3-(2-methylthioethoxy)-4-nitrophenylether,

2-chloro-α,α,α-trifluoro-p-tolyl-3-(1-ethyl-3-methylureido)-4-nitrophenylether,

2-bromo-α,α,α-trifluoro-p-tolyl-3-(2-methylsulfonylethoxy)-4-nitrophenylether,

α,α,α,α',α',α'-hexafluoro-2,4-xylyl-3-(3-methylureido)-4-nitrophenylether,2-cyano-α,α,α-trifluoro-p-tolyl-3-ethylthiocarbonylamido-4-nitrophenylether,

2-cyano-α,α,α-trifluoro-p-tolyl-3-cyano-4-nitrophenyl ether,

2,6-dichloro-α,α,α-trifluoro-p-tolyl-3-carboxy-4-nitrophenyl ether,

2-chloro-α,αα-trifluoro-p-tolyl-3-(1-carbamoylethoxy)-4-nitrophenylether,

2-bromo-α,α, α-trifluoro-p-tolyl-3-(3-oxobutoxy)-4-nitrophenyl ether,

and the like.

The novel diphenyl ethers of the invention are useful both aspreemergence and as postemergence herbicides. Preemergence herbicidesare ordinarily used to treat the soil in which the desired crop is to beplanted by application either before seeding, during seeding, or, as inmost applications, after seeding and before the crop emerges.Post-emergence herbicides are those which are applied after the plantshave emerged and during their growth period.

Among the crops on which the diphenyl ethers of the invention can beadvantageously employed are, for example, cotton, soybeans, peanuts,safflower, beans, peas, carrots, corn, wheat, and other cereal crops.

Diphenyl ethers of the invention are useful for controlling weeds inrice plants. When used in transplanted rice crops, the ethers can beapplied either preemergence or post-emergence to the weeds--that is,they can be applied to the growth medium of the transplanted plantseither before the weed plants have emerged or while they are in theirearly stages of growth. The ethers can be applied to the growth mediumeither before or after the rice has been transplanted to that medium.

The diphenyl ethers of the invention can be applied in any amount whichwill give the required control of weeds. A preferred rate of applicationof the herbicides of the invention is from about 0.1 to about 12, andmost preferably about 0.25 to 4, pounds of the diphenyl ether per acre.

Under some conditions, the diphenyl ethers of the invention may beadvantageously incorporated into the soil or other growth medium priorto planting a crop. This incorporation can be carried out by anyconvenient means, including by simple mixing with the soil, by applyingthe diphenyl ether to the surface of the soil and then disking ordragging into the soil to the desired depth, or by employing a liquidcarrier to accomplish the necessary penetration and impregnation.

A diphenyl ether of the invention can be applied to the growth medium orto plants to be treated either by itself or, as is generally done, as acomponent in a herbicidal composition or formulation which alsocomprises an agronomically acceptable carrier. By agronomicallyacceptable carrier is meant any substance which can be used to dissolve,disperse, or diffuse a herbicidal compound in the composition withoutimpairing the effectiveness of the herbicidal compound and which byitself has no detrimental effect on the soil, equipment, crops, oragronomic environment. Mixtures of the diphenyl ethers of the inventionmay also be used in any of these herbicidal formulations. The herbicidalcompositions of the invention can be either solid or liquid formulationsor solutions. For example, the diphenyl ethers can be formulated aswettable powders, emulsifiable concentrates, dusts, granularformulations, aerosols, or flowable emulsion concentrates. In suchformulations, the compounds are extended with a liquid or solid carrierand, when desired, suitable surfactants are incorporated.

It is usually desirable, particularly in postemergence applications, toinclude adjuvants, such as wetting agents, spreading agents, dispersingagents, stickers, adhesives, and the like, in accordance withagricultural practices. Examples of adjuvants which are commonly used inthe art can be found in the John W. McCutcheon, Inc. publication"Detergents and Emulsifiers Annual".

The diphenyl ether compounds of this invention can be dissolved in anyappropriate solvent. Examples of solvents which are useful in thepractice of this invention include alcohols, ketones, aromatichydrocarbons, halogenated hydrocarbons, dimethylformamide, dioxane,dimethyl sulfoxide, and the like. Mixtures of these solvents can also beused. The concentration of the solution can vary from about 2% to about98% with a preferred range being about 25 to about 75%.

For the preparation of emulsifiable concentrates, the diphenyl ether canbe dissolved in organic solvents, such as benzene, toluene, xylene,methylated naphthalene, corn oil, pine oil, o-dichlorobenzene,isophorone, cyclohexanone, methyl oleate, and the like, or in mixturesof these solvents, together with an emulsifying agent which permitsdispersion in water. Suitable emulsifiers include, for example, theethylene oxide derivatives of alkylphenols or long-chain alcohols,mercaptans, carboxylic acids, and reactive amines and partiallyesterified polyhydric alcohols. Solvent-soluble sulfates or sulfonates,such as the alkaline earth salts or amine salts ofalkylbenzenesulfonates and the fatty alcohol sodium sulfates, havingsurface-active properties can be used as emulsifiers either alone or inconjunction with an ethylene oxide reaction product. Flowable emulsionconcentrates are formulated similarly to the emulsifiable concentratesand include, in addition to the above components, water and astabilizing agent such as a water-soluble cellulose derivative or awater-soluble salt of a polyacrylic acid. The concentration of theactive ingredient in emulsifiable concentrates is usually about 10 to60% and in flowable emulsion concentrates, this can be as high as about75%.

Wettable powders suitable for spraying, can be prepared by admixing thecompound with a finely divided solid, such as clays, inorganic silicatesand carbonates, and silicas and incorporating wetting agents, stickingagents, and/or dispersing agents in such mixtures. The concentration ofactive ingredients in such formulations is usually in the range of about20 to 98%, preferably about 40 to 75%. A dispersing agent can constituteabout 0.5 to about 3% of the composition, and a wetting agent canconstitute from about 0.1 to about 5% of the composition.

Dusts can be prepared by mixing the compounds of the invention withfinely divided inert solids which may be organic or inorganic in nature.Materials useful for this purpose include, for example, botanicalflours, silicas, silicates, carbonates and clays. One convenient methodof preparing a dust is to dilute a wettable powder with a finely dividedcarrier. Dust concentrates containing about 20 to 80% of the activeingredient are commonly made and are subsequently diluted to about 1 to10% use concentration.

Granular formulations can be prepared by impregnating a solid such asgranular fuller's earch, vermiculite, ground corn cobs, seed hulls,including bran or other grain-hulls, or similar material. A solution ofone or more of the diphenyl ethers in a volatile organic solvent can besprayed or mixed with the granular solid and the solvent then removed byevaporation. The granular material can have any suitable size, with apreferable size range of 16 to 60 mesh. The diphenyl ether will usuallycomprise about 2 to 15% of the granular formulation.

The diphenyl ethers of the invention can also be mixed with fertilizersor fertilizing materials before their application. In one type of solidfertilizing composition in which the diphenyl ethers can be used,particles of a fertilizer or fertilizing ingredients, such as ammoniumsulfate, ammonium nitrate, or ammonium phosphate, can be coated with oneor more of the ethers. The solid diphenyl ethers and solid fertilizingmaterial can also be admixed in mixing or blending equipment, or theycan be incorporated with fertilizers in granular formulations. Anyrelative proportion of diphenyl ether and fertilizer can be used whichis suitable for the crops and weeds to be treated. The diphenyl etherwill commonly be from about 5 to about 25% of the fertilizingcomposition. These compositions provide fertilizing materials whichpromote the rapid growth of desired plants, and at the same time controlthe growth of undesired plants.

The diphenyl ethers of the invention can be applied as herbicidal spraysby methods commonly employed, such as conventional high-gallonagehydraulic sprays, low gallonage sprays, airblast spray, aerial spraysand dusts. For low volume applications a solution of the compound isusually used. The dilution and rate of application will usually dependupon such factors as the type of equipment employed, the method ofapplication, the area to be treated and the type and stage ofdevelopment of the weeds.

For some applications, it may be desirable to add one or more otherherbicides along with diphenyl ethers of the invention. Examples ofother herbicides which can be incorporated to provide additionaladvantages and effectiveness include:

Carboxylic Acids and Derivatives

2,3,6-trichlorobenzoic acid and its salts

2,3,5,6-tetrachlorobenzoic acid and its salts

2-methoxy-3,5,6-trichlorobenzoic acid and its salts

2-methoxy-3,6-dichlorobenzoic acid and its salts

2-methyl-3,6-dichlorobenzoic acid and its salts

2,3-dichloro-6-methylbenzoic acid and its salts

2,4-dichlorophenoxyacetic acid and its salts and esters

2,4,5-trichlorophenoxyacetic acid and its salts and esters

2-methyl-4-chlorophenoxyacetic acid and its salts and esters

2-(2,4,5-trichlorophenoxy)propionic acid and its salts and esters

4-(2,4-dichlorophenoxy)butyric acid and its salts and esters

4-(2-methyl-4-chlorophenoxy)butyric acid and its salts and esters

2,3,6-trichlorophenylacetic acid and its salts

3,6-endoxohexahydrophthalic acid

dimethyl 2,3,5,6-tetrachloroterephthalate

trichloroacetic acid and its salts

2,2-dichloropropionic acid and its salts

2,3-dichloroisobutyric acid and its salts

Carbamic Acid Derivatives

ethyl N,N-di(n-propyl)thiolcarbamate

propyl N,N-di(n-propyl)thiolcarbamate

ethyl N-ethyl-N-(n-butyl)thiolcarbamate

propyl N-ethyl-N-(n-butyl)thiolcarbamate

2-chloroallyl N,N-diethyldithiocarbamate

N-methyldithiocarbamic acid salts

ethyl 1-hexamethyleneiminecarbothiolate

isopropyl N-phenylcarbamate

isopropyl N-(m-chlorophenyl)carbamate

4-chloro-2-butynyl N-(m-chlorophenyl)carbamate

methyl N-(3,4-dichlorophenyl)carbamate

Phenols

dinitro-o-(sec-butyl)phenol and its salts

pentachlorophenol and its salts

Substituted Ureas

3-(3,4-dichlorophenyl)-1,1-dimethylurea

3-phenyl-1,1-dimethylurea

3-(3,4-dichlorophenyl)-3-methoxy-1,1-dimethylurea

3-(4-chlorophenyl)-3-methoxy-1,1-dimethylurea

3-(3,4-dichlorophenyl)-1-n-butyl-1-methylurea

3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea

3-(4-chlorophenyl)-1-methoxy-1-methylurea

3-(3,4-dichlorophenyl)-1,1,3-trimethylurea

3-(3,4-dichlorophenyl)-1,1-diethylurea

dichloral urea

Substituted Triazines

2-chloro-4,6-bis(ethylamino)-s-triazine

2-chloro-4-ethylamino-6-isopropylamino-s-triazine

2-chloro-4,6-bis(methoxypropylamino)-s-triazine

2-methoxy-4,6-bis(isopropylamino)-s-triazine

2-chloro-4-ethylamino-6-(3-methoxypropylamino)-s-triazine

2-methylmercapto-4,6-bis(isopropylamino)-s-triazine

2-methylmercapto-4,6-bis(ethylamino)-s-triazine

2-methylmercapto-4-ethylamino-6-isopropylamino-s-triazine

2-chloro-4,6-bis(isopropylamino)-s-triazine

2-methoxy-4,6-bis(ethylamino)-s-triazine

2-methoxy-4-ethylamino-6-isopropylamino-s-triazine

2-methylmercapto-4-(2-methoxyethylamino)-6-isopropylamino-s-triazine

Diphenyl Ether Derivatives

2,4-dichloro-4'-nitrodiphenyl ether

2,4,6-trichloro-4'-nitrodiphenyl ether

2,4-dichloro-6-fluoro-4'-nitrodiphenyl ether

3-methyl-4'-nitrodiphenyl ether

3,5-dimethyl-4'-nitrodiphenyl ether

2,4'-dinitro-4-trifluoromethyldiphenyl ether

2,4-dichloro-3'-methoxy-4'-nitrodiphenyl ether

Anilides

N-(3,4-dichlorophenyl)propionamide

N-(3,4-dichlorophenyl)methacrylamide

N-(3-chloro-4-methylphenyl)-2-methylpentanamide

N-(3,4-dichlorophenyl)trimethylacetamide

N-(3,4-dichlorophenyl)-α,α-dimethylvaleramide

N-isopropyl-N-phenylchloroacetamide

N-n-butoxymethyl-N-(2,6-diethylphenyl)chloroacetamide

N-n-methoxymethyl-N-(2,6-diethylphenyl)chloroacetamide

Uracils

5-bromo-3-s-butyl-6-methyluracil

5-bromo-3-cyclohexyl-1,6-dimethyluracil

3-cyclohexyl-5,6-trimethyleneuracil

5-bromo-3-isopropyl-6-methyluracil

3-tert-butyl-5-chloro-6-methyluracil

Nitriles

2,6-dichlorobenzonitrile

diphenylacetonitrile

3,5-dibromo-4-hydroxybenzonitrile

3,5-diiodo-4-hydroxybenzonitrile

Other Organic Herbicides

2-chloro-N,N-diallylacetamide

N-(1,1-dimethyl-2-propynyl)-3,5-dichlorobenzamide

maleic hydrazide

3-amino-1,2,4-triazole

monosodium methanearsonate

disodium methanearsonate

N,n-dimethyl-α,α-diphenylacetamide

N,n-di(n-propyl)-2,6-dinitro-4-trifluoromethylaniline

N,n-di(n-propyl)-2,6-dinitro-4-methylaniline

N,n-di(n-propyl)-2,6-dinitro-4-methylsulfonylaniline

O-(2,4-dichlorophenyl)-O-methyl-isopropylphosphoramidothioate

4-amino-3,5,6-trichloropicolinic acid

2,3-dichloro-1,4-naphthoquinone

di(methoxythiocarbonyl)disulfide

3-isopropyl-1H-2,1,3-benzothiadiazin-(4)3H-one-2,2-dioxide

6,7-dihydrodipyridol[1,2-a:2',1'-c]pyrazidinium salts

1,1'-dimethyl-4,4'-bipyridinium salts

3,4,5,6-tetrahydro-3,5-dimethyl-2-thio-2H-1,3,5-thiadiazine.

When mixtures of herbicides are employed, the relative proportions whichare used will depend upon the crop to be treated and the degree ofselectivity in weed control which is desired.

The diphenyl ethers of the invention or their precursors can be preparedby reacting a suitably substituted phenol, or the potassium or sodiumsalt of the phenol, with a suitably substituted halobenzene, such as achloro- or fluorobenzene, in the presence of an alkaline agent.

The following examples will further illustrate this invention but arenot intended to limit it in any way. In Table I, typical phenyl ethersof the invention are listed, with their melting points and elementalanalyses. Specific, illustrative preparations of the compounds ofExamples 3, 7, 10, 19, 21, 25, 26, 37, 47, 48, 49, 51, 55, and 56 aredescribed after Table I.

                                      TABLE I                                     __________________________________________________________________________    Diphenyl Ethers - Physical Data                                                ##STR3##                                                                                                           Analysis                                Example No.                                                                           X  Y Z           m.p. (° C)                                                                          %C   %H   %N   %Cl  %F                  __________________________________________________________________________    1       H  H OC.sub.2 H.sub.5                                                                          72-75    found                                                                             54.67                                                                              3.75 4.19      15.25                                                 reqs.                                                                             55.05                                                                              3.70 4.28      17.42               2       Cl H OCH.sub.3   95-100   found                                                                             48.78                                                                              2.89 4.01 9.65 14.91                                                 reqs.                                                                             48.33                                                                              2.61 4.03 10.20                                                                              16.40               3       Cl H OC.sub.2 H.sub.5                                                                          83-84    found                                                                             49.85                                                                              3.33 3.68 9.90 15.51                                                 reqs.                                                                             49.80                                                                              3.07 3.87 9.80 15.75               4       Cl H OC.sub.3 H.sub.7 -i                                                                       49.5-51  found                                                                             51.02                                                                              3.58 3.52 9.62 15.58                                                 reqs.                                                                             51.18                                                                              3.49 3.73 9.42 15.16               5       Cl H OC.sub.3 H.sub.7 -n                                                                       75-76    found                                                                             51.36                                                                              3.60 3.62 9.34 15.00                                                 reqs.                                                                             51.18                                                                              3.49 3.73 9.42 15.16               6       Cl H OC.sub.4 H.sub.9 -n                                                                       51-52    found                                                                             52.07                                                                              4.03 3.38 9.28 14.65                                                 reqs.                                                                             52.42                                                                              3.88 3.59 9.10 14.63               7       CN H OC.sub.2 H.sub.5                                                                          143-145  found                                                                             54.84                                                                              3.36 8.01      15.85                                                 reqs.                                                                             52.18                                                                              3.01 7.61      15.48               8       CN H OC OC.sub.3 H.sub.7 -n                                                                    96.5-98  found                                                                             55.70                                                                              3.65 7.56                                                            reqs.                                                                             55.74                                                                              3.58 7.65      15.56               9       CN H CH.sub.3    86-88.5  found                                                                             55.95                                                                              2.80 8.62      17.68                                                 reqs.                                                                             55.90                                                                              2.81 8.72      17.69               10      Cl H OH          68-70    found                                                                             47.07                                                                              2.11 4.00 10.76                                                                              17.00                                                 reqs.                                                                             46.79                                                                              2.12 4.20 10.63                                                                              17.08               11      Cl H OCH.sub.2 CF.sub.3                                                                        78-80    found                                                                             43.30                                                                              1.77 3.22 8.60 27.60                                                 reqs.                                                                             43.35                                                                              1.94 3.37 8.54 27.40               12      Cl H OCH.sub.2 CHCH.sub.2                                                                      76.78.5  found                                                                             51.76                                                                              2.77 3.75 9.51 15.32                                                 reqs.                                                                             5.42 2.97 3.75 9.48 15.25               13      Cl H OCH.sub.2 CCH                                                                             89-93    found                                                                             51.83                                                                              2.22 3.52 9.61 15.31                                                 reqs.                                                                             51.70                                                                              2.44 3.77 9.54 15.33               14      Cl H OCH.sub.2 CH.sub.2 CCCH.sub.3                                                             93-94    found                                                                             53.99                                                                              2.95 3.35 8.93 14.12                                                 reqs.                                                                             54.10                                                                              3.28 3.50 8.87 14.25               15      Cl H OCH.sub.2 CH.sub.2 OH                                                                     76-77    found                                                                             47.53                                                                              2.92 3.55 9.88 14.98                                                 reqs.                                                                             47.70                                                                              2.94 3.71 9.38 15.09               16      Cl H OCH.sub.2 CH.sub.2 OC.sub.2 H.sub.5                                                       62-64    found                                                                             50.75                                                                              3.82 3.37 8.48 14.00                                                 reqs.                                                                             50.32                                                                              3.73 3.45 8.74 14.05               17      Cl H OCH.sub.2 CH.sub.2 N(CH.sub.3).sub.2                                                      oil      found                                                                             50.30                                                                              3.76 6.42 9.19 13.80                                                 reqs.                                                                             50.44                                                                              3.98 6.92 8.76 14.08               18      Cl H OCOCH.sub.3 85-89    found                                                                             47.82                                                                              2.50 3.65 9.58 14.79                                                 reqs.                                                                             47.90                                                                              2.42 3.73 9.44 15.20               19      Cl H NHC.sub.2 H.sub.5                                                                         82-83    found                                                                             50.01                                                                              3.23 7.82 9.95 15.48                                                 reqs.                                                                             49.94                                                                              3.35 7.77 9.83 15.80               20      Cl H N(CH.sub.3).sub.2                                                                         82-83    found                                                                             50.27                                                                              3.46 7.95 9.62 15.50                                                 reqs.                                                                             49.97                                                                              3.35 7.77 9.83 15.80               21      Cl H N(C.sub.2 H.sub.5).sub.2                                                                  *170° C/0.01mm                                                                  found                                                                             52.80                                                                              3.89 7.10 9.25 14.58                                                 reqs.                                                                             52.50                                                                              4.15 7.20 9.12 14.68               22      Cl H NHCH.sub.2 CH.sub.2 OH                                                                    85-87    found                                                                             46.22                                                                              3.33 7.06 8.50 15.30                                                 reqs.                                                                             47.82                                                                              3.21 7.44 9.42 15.13               23      Cl H OCH.sub.2 CO.sub.2 H                                                                      94-96    found                                                                             45.96                                                                              2.21 3.71 9.17 13.99                                                 reqs.                                                                             46.00                                                                              2.32 3.57 9.05 14.56               24      Cl H OCH.sub.2 CO.sub.2 C.sub.2 H.sub.5                                                        76-77    found                                                                             48.49                                                                              2.93 3.25 8.58 13.65                                                 reqs.                                                                             48.60                                                                              3.13 3.34 8.46 13.62               25      Cl H OCH(CH.sub.3)CO.sub.2 H                                                                   108-109  found                                                                             47.34                                                                              2.63 3.52 8.78 13.70                                                 reqs.                                                                             47.35                                                                              2.73 3.45 8.73 14.05               26      Cl H OCH(CH.sub.3)CO.sub.2 C.sub.2 H.sub.5                                                     71-72.5  found                                                                             49.78                                                                              3.40 3.07 8.31 12.90                                                 reqs.                                                                             49.85                                                                              3.49 3.23 8.18 13.15               27      Cl H NH.sub.2    85.5-89.5                                                                              found                                                                             48.6 2.87 8.01 10.37                                                                              17.09                                                 reqs.                                                                             46.93                                                                              2.42 8.42 10.66                                                                              17.14               28      Cl H                                                                                ##STR4##   *180-185/                                                                              found                                                                             50.61                                                                              3.39 6.80 8.95 13.71                                        0.04mm   reqs.                                                                             50.70                                                                              3.50 6.96 8.80 14.15               29      CL H OCH.sub.2 CH.sub.2 CCH                                                                    104-105.5                                                                              found                                                                             52.67                                                                              3.05 3.44 9.41 14.33                                                 reqs.                                                                             53.00                                                                              2.87 3.63 9.20 14.80               30      Cl H OCH(CH.sub.3)CCH                                                                          40-42    found                                                                             52.59                                                                              2.77 3.61 9.66 15.27                                                 reqs.                                                                             53.00                                                                              2.87 3.63 9.20 14.80               31      Cl H OCH.sub.2 CH.sub.2 COCH.sub.3                                                             74-76    found                                                                             50.44                                                                              3.27 3.36 8.81 14.49                                                 reqs.                                                                             50.60                                                                              3.25 3.47 8.75 14.12               32      Cl H OCH(CH.sub.3)COCH.sub.3                                                                   oil      found                                                                             48.07                                                                              3.26 3.17 8.18 14.26                                                 reqs.                                                                             50.60                                                                              3.25 3.47 8.75 14.12               33      Cl H OCONHCH.sub.3                                                                             85-88    found                                                                             45.57                                                                              3.21 8.02 9.48 14.76                                                 reqs.                                                                             46.10                                                                              2.58 7.18 9.08 14.60               34      Cl H NHCOC.sub.2 H.sub.5                                                                       oil      found                                                                             49.50                                                                              3.14 7.01 9.12 14.71                                                 reqs.                                                                             49.40                                                                              3.12 7.20 9.12 14.68               35      Cl H NHCOCH.sub.2 Cl                                                                           oil      found                                                                             44.51                                                                              1.85 6.60 17.34                                                                              14.90                                                 reqs.                                                                             44.03                                                                              2.22 6.85 17.33                                                                              13.93               36      Cl H CH.sub.3    *135° C/                                                                        found                                                                             50.91                                                                              2.81 4.31 10.63                                                                              16.95                                        0.08mm   reqs.                                                                             50.70                                                                              2.73 4.22 10.69                                                                              17.19               37      Cl H Cl          *153° C/                                                                        found                                                                             44.15                                                                              1.58 4.09 18.13                                                                              18.48                                        0.24mm   reqs.                                                                             44.34                                                                              1.72 3.98 20.14                                                                              16.19               38      Cl H                                                                                ##STR5##   49-53    found                                                                             47.88                                                                              2.50 3.32 10.58                                                                              14.82                                                 reqs.                                                                             49.30                                                                              2.84 3.60 9.11 14.63               39      Cl H OCH.sub.2 CHOHCH.sub.2 OH                                                                 59-64    found                                                                             47.49                                                                              3.32 3.35 8.88 14.73                                                 reqs.                                                                             49.00                                                                              3.35 3.58 9.05 14.58               40      Cl H OCH.sub.2 CH.sub.2 SCH.sub.3                                                              42-45    found                                                                             47.09                                                                              2.95 3.34 8.80 14.05                                                 reqs.                                                                             47.12                                                                              3.21 3.44 8.69 13.98               41      Cl H N(C.sub.3 H.sub.7 -n).sub.2                                                               oil      found                                                                             54.04                                                                              4.62 6.34 8.71 13.55                                                 reqs.                                                                             54.75                                                                              4.84 6.72 8.50 13.67               42      Cl H OCH.sub.2 CH.sub.2 SO.sub.2 CH.sub.3                                                      127.5-129.5                                                                            found                                                                             43.53                                                                              2.71 2.99 8.27 13.19                                                 reqs.                                                                             43.69                                                                              2.98 3.19 8.06 12.96               43      Cl H N(CH.sub.3)CH.sub.2 CH.sub.2 OH                                                           oil      found                                                                             48.95                                                                              3.65 7.18 9.29 14.87                                                 reqs.                                                                             49.18                                                                              3.61 7.17 9.07 14.59               44      Cl H NHCONHCH.sub.3                                                                            204-208  found                                                                             46.52                                                                              2.56 10.76                                                                              9.40 14.47                                                 reqs.                                                                             46.22                                                                              2.85 10.78                                                                              9.10 14.63               45      Cl H NHCOSC.sub.2 H.sub.5                                                                      111-112  found                                                                             45.76                                                                              2.88 6.77 8.58 13.24                                                 reqs.                                                                             45.66                                                                              2.88 6.66 8.42 13.55               46      Cl H N(COSC.sub.2 H.sub.5).sub.2                                                               99-100   found                                                                             45.08                                                                              3.14 5.53 7.20 11.03                                                 reqs.                                                                             44.84                                                                              3.17 5.50 6.97 11.20               47      Cl H CN          95-103   found                                                                             49.92                                                                              1.82 7.68 11.57                                                                              15.69                                                 reqs.                                                                             49.05                                                                              1.77 8.18 10.35                                                                              16.65               48      Cl H CO.sub.2 H  140-150  found                                                                             46.26                                                                              1.86 3.45 11.03                                                                              14.48                                                 reqs.                                                                             46.50                                                                              1.95 3.87 9.82 15.78               49      Cl H CO.sub.2 CH.sub.3                                                                         oil      found                                                                             47.77                                                                              2.64 3.48 10.49                                                                              12.93                                                 reqs.                                                                             47.90                                                                              2.42 3.73 9.45 15.20               50      Cl H OCH(CH.sub.3)CO.sub.2 CH.sub.3                                                            68-70    found                                                                             48.58                                                                              2.98 3.15 8.58 13.73                                                 reqs.                                                                             48.60                                                                              2.98 3.35 8.43 13.58               51      Cl H OCH(CH.sub.3)CONH.sub.2                                                                   108-111  found                                                                             47.61                                                                              3.21 6.70 8.98 14.37                                                 reqs.                                                                             47.50                                                                              2.99 6.93 8.78 14.10               52      Cl H OCH(CH.sub.3)CONHCH.sub.3                                                                 121-126  found                                                                             48.68                                                                              3.53 6.54 8.78 13.72                                                 reqs.                                                                             48.80                                                                              3.37 6.70 8.48 13.62               53      Cl H OCH(CH.sub.3)CON(CH.sub.3).sub.2                                                          83-85    found                                                                             50.17                                                                              3.78 6.25 8.37 13.22                                                 reqs.                                                                             50.00                                                                              3.73 6.48 8.20 13.18               54      Cl H N(C.sub.2 H.sub.5)CH.sub.2 CH.sub.2 OH                                                             found                                                                             50.44                                                                              3.99 6.92 8.76 14.08                                                 reqs.                                                                             50.27                                                                              4.10 6.89 8.86 14.18               55      Cl H N(C.sub.2 H.sub.5)CONHCH.sub.3                                                            127.5-128.5                                                                            found                                                                             49.51                                                                              3.91 9.95 8.64 12.60                                                 reqs.                                                                             48.87                                                                              3.62 10.06                                                                              8.49 13.64               56      Cl Cl                                                                              OC.sub.2 H.sub.5                                                                          100.5-102                                                                              found                                                                             45.26                                                                              2.43 3.36 18.00                                                                              12.33                                                 reqs.                                                                             45.47                                                                              2.54 3.54 17.90                                                                              14.39               __________________________________________________________________________     *boiling point                                                           

EXAMPLE 3 Preparation of2-Chloro-α,α,α-trifluoro-p-tolyl-3-ethoxy-4-nitrophenyl ether

Method A

a. 1,3-Bis(2-chloro-α,α,α-trifluoro-p-tolyloxy)benzene

A solution of potassium hydroxide (3.26 g. 0.05 mole, 85%) in water (˜3g.) is added slowly dropwise to a solution of resorcinol (2.75 g. 0.025mole) and 3,4-dichloro-α,α,α-trifluorotoluene (10.75 g. 0.05 mole) insulfolane (125 ml) at 150°-160° C., with stirring. When the addition iscomplete, the strongly colored reaction mixture is stirred at 150°-160°C. overnight, then cooled, diluted with benzene (200 ml), and washedcautiously with water (700 ml). Hexane (200 ml) is added and the mixturewashed with water (600 ml), dilute sulfuric acid (600 ml), dilute sodiumhydroxide solution (600 ml), and water (600 ml), dried, and the solventremoved to give 1,3-bis(2-chloro-α,α,α-trifluoro-p-tolyloxy)benzene (8.6g 65%) b.p. 160°-70° C./0.1 mm.

b. 1,3-Bis(2-chloro-α,α,α-trifluoro-p-tolyloxy)-4-nitrobenzene

1,3-Bis(2-chloro-α,α,α-trifluoro-p-tolyloxy)benzene (12 g. 0.0255 mole)is added to a mixture of concentrated nitric acid (12 g.) and sulfuricacid (15 g.) at 5° C. The temperature is then allowed to rise to 25°-30°C. with manual stirring and mild ice bath cooling and after 10-20minutes, the oil solidifies. The mixture is taken up in water/benzene(400 ml)/hexane (400 ml) and the organic phase is washed with water,dried, filtered through activated silica gel (˜20 g.), and the solventsremoved. The residue is recrystallized from isopropanol to give1,3-bis(2-chloro-α,αα-trifluoro-p-tolyloxy)-4-nitrobenzene, (7.4 g. 56%)m.p. 110°-111.5° C.

c. 2-Chloro-α,α,α-trifluoro-p-tolyl-3-ethoxy-4-nitrophenylether

A 10% solution of potassium hydroxide in ethanol (10 ml) is added to asolution of 1,3-bis(2-chloro-α,α,α-trifluoro-p-tolyloxy)-4-nitrobenzene(2 g. 0.0039 mole) in dioxane (20 ml). After 40 minutes at roomtemperature, the solution is heated to 45° C. for 8 minutes, thencooled, diluted with benzene (50 ml) and hexane (50 ml) and washed withwater (3 × 100 ml), dried, and the solvents removed. The residue isrecrystallized from ispropanol to give2-chloro-α,α,α-trifluoro-p-tolyl-3-ethoxy-4-nitrophenylether (1.21 g.86%) m.p. 83°-84° C.

method B

a. 2-Chloro-α,α,α-trifluoro-p-tolyl-3-hydroxyphenyl ether

A mixture of the di-potassium salt of resorcinol (186.3 g., 1 mol),3,4-dichloro-α,α,α-trifluorotoluene (53.7 g., 0.25 mol), and sulfolane(100 ml.) is stirred for 30 hours at 140°-160° C.

Benzene (500 ml) and water (200 ml) are added and the organic phase iswashed with water (3 × 200 ml), diluted with hexane (500 ml) and washedagain with water, dried, filtered through activated silica gel (15 g.),the solvents removed, and the residue distilled to give2-chloro-α,α,α-trifluoro-p-tolyl-3-hydroxyphenyl ether (45.1 g., 62%)b.p. 112°-124° C./0.3 mm.

b. 2-Chloro-α,α,α-trifluoro-p-tolyl-3-acetoxyphenyl ether

A mixture of 2-chloro-α,α,α-trifluoro-p-tolyl-3-hydroxyphenylether (184g.) and acetic anhydride (334 g.) is heated on a steam bath for 1 hourand cooled. The mixture is washed with 5% sodium carbonate solution (2 ×500 ml.) and distilled to give 2-chloro-α ,α,α-trifluoro-p-tolyl-3-acetoxyphenyl ether (84 g., 40%) b.p. 107°-117°C./0.09 mm.

c. 2-Chloro-α ,α ,α-trifluoro-p-tolyl-3-acetoxy-4-nitrophenyl ether

A solution of 2-chloro-α ,α ,α-trifluoro-p-tolyl-3-acetoxyphenyl ether(249 g., 0.75 mol) in 1,2-dichloroethane (1200 ml.) is stirred 2.2 hoursat 20°-30° C. with a cooled mixture of concentrated sulfuric acid(276g.) and nitric acid, 70% (227 g.). Hexane (700 ml.) is added and theoil layer washed once with water, 3 times with dilute sodiumbicarbonate, and once more with water, dried, filtered through activatedsilica gel (˜40 g.), the solvents removed. The product is crystallizedfrom hexane-benzene to give 2-chloro-α ,α,α-trifluoro-p-tolyl-3-acetoxy-4-nitrophenyl ether (207.5 g., 73%)m.p.83°-89° C.

d. 2-Chloro-α ,α ,α-trifluoro-p-tolyl-3-hydroxy-4-nitrophenyl ether

A solution of 2-chloro-α ,α ,α-trifluoro-p-tolyl-3-acetoxy-4-nitrophenylether (204.9 g., 0.545 mol) in methanol (2900 ml.) is stirred 1 hour at20° C. with potassium carbonate (103 g., 0.745 mol). Ninety per cent ofthe methanol is removed; and benzene (1 liter), 7-8% sulfuric acidsolution (1600 ml.) are added and stirred 1.5 hours at 25° C. The oillayer is washed twice more with water (200 ml. each), dried, filteredthrough activated silica gel (40 g.), the solvents removed, and theresidue crystallized in hexane to give 2-chloro-α,α ,α-trifluoro-p-tolyl-3-hydroxy-4-nitrophenyl ether (165.3 g. 90%)m.p.68.5°-73° C.

e. 2-Chloro-α,α ,α -trifluoro-p-tolyl-3-ethoxy-4-nitrophenyl ether

A solution of 2-chloro-α,α ,α-trifluoro-p-trifluoro-p-tolyl-3-hydroxy-4-nitrophenyl ether (60 g.,0.018 mol, 73% pure) and dimethylformamide (100 g.) is converted to thepotassium phenoxide and stirred with ethyl bromide (35 g., 0.32 mol) 3hours at 60° C. and 5 hours at 80° C. Perchlorethylene (150 g.) is addedand the solution washed twice with water (˜250 ml. each) at 50° C. Thesolvents are removed to give 2-chloro-α,α ,α-trifluoro-p-tolyl-3-ethoxy-4-nitrophenyl ether (56 g., 83%, 71% pure).

EXAMPLE 7 Preparation of 2-Cyano-α,α,α-trifluoro-p-tolyl-3-ethoxy-4-nitrophenyl ether

A solution of potassium hydroxide (2.6 g., 0.04 mole) 87.3% pure and3-ethoxy-4-nitrophenol (7.3 g., 0.04 mole) in methanol (30 ml) isstripped to dryness under reduce pressure. A residue of potassium3-ethoxy-4-nitrophenoxide is dissolved in sulfolane (200 g.) and4-chloro-3-cyano-benzotrifluoride (8.2 g., 0.04 mole) is added.Gas-liquid chromotography shows the reaction to be complete afterstirring at 110° C. for 41/2 hours and 135° C. for 21/2hours. Thereaction mixture is cooled and poured into deionized water and theprecipitate which forms is filtered off and air dried. Recrystallizationfrom isopropanol yields 2-cyano-α,α ,α-trifluoro-p-tolyl-3-ethoxy-4-nitrophenyl ether (7.4 g. 53%) m.p.143°-145° C.

EXAMPLE 19 Preparation of 2-Chloro-α,α ,α-trifluoro-p-tolyl-3-ethylamino- 4-nitrophenyl ether

A solution of 1,3-bis(2-cholor-α,α ,α-trifluoro-p-tolyloxy)-4-nitrobenzene (12.8 g. 0.025 mol), andethylamine (6.7 g. 0.15 mol) in dioxane (120 ml.) is heated in apressure bottle 4.5 hours at 50°-55° C. and 4.3 hours at 90°-95° C.Benzene (200 ml.), hexane (70 ml.) and water (500 ml.) are added and theorganic phase is washed with water (500 ml.), 10% sodium bicarbonatesolution (200 ml.) and water (200 ml), dried, filtered through activatedsilica gel (25 g.), the solvents removed, and the residue iscrystallized from hexane to give 2-chloro-α,α ,α-trifluoro-p-tolyl-3-ethylamino-4-nitrophenyl ether (7.9 g. 88%) m.p.82°-83° C.

EXAMPLE 21 Preparation of 2-Chloro-α,α ,α-trifluoro-p-tolyl-3-diethylamino-4-nitrophenyl ether

A solution of 1,3-bis(2-chloro-α,α ,α-trifluoro-p-tolyloxy)-4-nitrobenzene (12.8 g. 0.025 mol) in p-dioxane(130 ml.) is heated under reflux for 26 hours at 65°-95° C. withdiethylamine (50 g. 0.66 mol). Benzene (˜200 ml.) and water (˜500 ml.)are added followed by hexane (˜70 ml.) and the oil layer is separated,washed with water (500 ml), 10% sodium bicarbonate solution (200 ml),and water (200 ml.), dried, filtered through activated silica gel (˜25g.), the solvents removed. The residual oil is distilled in vacuo togive 2-chloro-α,α ,α -trifluoro-p-tolyl-3-diethylamino-4-nitrophenylether (8.15 g 84%) b.p. 180°-190° C./0.01 mm.

EXAMPLE 25 Preparation of 2-Chloro-α,α ,α-trifluoro-p-tolyl-3-(1-carboxyethoxy)-4-nitrophenyl ether

2-Chloro-α,α ,α -trifluoro-p-tolyl-3-(1-carbethoxyethoxy)-4-nitrophenylether (8.6 g. 0.02 mol), potassium hydroxide 86% (2.6 g. 0.04 mol),ethanol (8 ml.), dioxane (8 ml.), and water (100 ml.) are heated at90°-95° C. for 30 minutes. Ether (200 ml.) and water (200 ml.) are addedand the mixture acidified with dilute sulfuric acid, the water layerextracted three times with ether (200 ml. each), dried, and the etherremoved to give 2-chloro-α ,α ,α-trifluoro-p-tolyl-3-(1-carboxyethoxy)-4-nitrophenyl ether (6.4 g. 79%)m.p. 108°-109° C.

EXAMPLE 26 Preparation of 2-Chloro-α,α ,α-trifluoro-p-tolyl-3-(1-carbethoxyethoxy)-4-nitrophenyl ether

Potassium 2-nitro-5-(2-chloro-α,α ,α -trifluoro-p-tolyloxy)phenoxide(7.4 g. 0.02 mol), ethyl 2-bromopropionate (3.6 g. 0.02 mol) andsulfolane (50 ml.) are heated 1.5 hours at 90°-95° C. Benzene (100 ml.)and hexane (100 ml.) are added and the solution is washed with dilutesodium carbonate solution then with water, dried, and the solventsremoved. The residue is crystallized from pentane to give 2-chloro-α, ,α-trifluoro-p-tolyl-3-(1-carbethoxyethoxy)-4-nitrophenyl ether (6.2 g.,71%) m.p. 71°-74° C.

EXAMPLE 27 Preparation of 2-chloro-α,α ,α-trifluoro-p-tolyl-3-chloro-4-nitrophenyl ether

a. 3-Chloro-4-nitrofluorobenzene

m-Chlorofluorobenzene (240 g. 1.85 moles) is added to a mixture ofsulfuric acid (185 g. 1.85 moles) and nitric acid (166 g., 1.85 moles)at -5° C. in 3.5 hours, stirred 13 hours, then benzene (200 ml.) andhexane (200 ml.) are added. The extract is washed with water (1 × 300ml.), sodium carbonate solution (1 × 300 ml.), and water (1 × 300 ml.),dried and the solvents removed. The residue is distilled to give 138 g.of mixed isomers. The 4-nitro isomer crystallizes and is filtered off togive 3-chloro-4-nitrofluorobenzene (51 g. 16.7%) m.p. 36°-38° C.

EXAMPLES 47-49 Preparation of 2-chloro-α,α ,α-trifluoro-p-tolyl-3-carbomethoxy-4-nitrophenyl ether

a. 3-Cyano-4-nitrofluorobenzene

m-Fluorobenzonitrile (96.8 g., 0.8 mole) is added in two and one-halfhours to a mixture of concentrated sulfuric acid (600 ml.) and potassiumnitrate (80.9 g., 0.8 mole) at 3°-6° C., then allowed to warm to 25° C.The mixture is poured over cracked ice (3000 ml.), extracted withchloroform (5 × 250 ml.), dried and the solvent removed. The residue isextracted with pentane and dried to give 3-cyano-4-nitrofluorobenzene(115 g., 86.5%) m.p. 102°-104° C.

b. 2-Chloro-α,α ,α -trifluoro-p-tolyl-3-cyano-4-nitrophenyl ether

The potassium phenoxide of 2-chloro-α,α ,α -trifluoro-p-cresol (13.5 g0.0688 mole) prepared in sulfolane at 5° C. is added to a solution of3-cyano-4-nitrofluorobenzene (11.4 g., 0.0688 mole) in sulfolane at 120°C. in four hours, stirred 18 hours and cooled. Benzene (200 ml.) andhexane (100 ml) are added and the solution is water washed (5 × 250ml.), dried, filtered and the solvents removed. The residue iscrystallized to give 2-chloro-α,α ,α -p-tolyl-3-cyano-4-nitrophenylether (16.3 g., 69%) m.p. 95°-103° C. 85% pure.

c. 2-Chloro-α,α ,α -trifluoro-p-tolyl-3-carboxy-4-nitrophenyl ether

2-Chloro-α,α ,α -trifluoro-p-tolyl-3-cyano-4-nitrophenyl ester (11.2 g.0.0327 mole), acetic acid (25 ml.), and hydrobromic acid (12 ml. of47.8% purity) are heated at 120° C., in a pressure bottle, for two days,poured over cracked ice and extracted with benzene (2 × 150 ml). Thebenzene solution is dried, filtered, the solvent removed, and theresidue crystallized from pentane to give 2-chloro-α,α ,α-trifluoro-p-tolyl-3-carboxy-4-nitrophenyl ether (7.5 g. 63.5%) m.p.140°-150° C., 85% pure.

d. 2-Chloro-α,α ,α -trifluoro-p-tolyl-3-carbomethoxy-4-nitrophenylether

Hydrogen chloride is bubbled thru a solution of 2-chloro-α,α ,α-trifluoro-p-tolyl-3-carboxy-4-nitrophenyl ether (2.3 g. 0.0064 mole) inmethanol (50 ml.) for 10 hours at 32° C., stirred overnite and thesolvent removed to give 2-chloro-α,α ,α-trifluoro-p-tolyl-3-carbomethoxy-4-nitrophenyl ether (1.5 g. 40%)

EXAMPLE 51 Preparation of 2-chloro-α,α ,α-trifluoro-p-tolyl-3-(1-carbamoylethoxy)-4-nitrophenyl ether

a. 2-Chloro-α,α ,α-trifluoro-p-tolyl-3-(1-chloroformylethoxy)-4-nitrophenyl ether

2-Chloro-α,α ,α -trifluoro-p-tolyl-3-(1-carboxyethoxy)-4-nitrophenylether (34.8 g. 0.086 mol), thionyl chloride (20.4 g. 0.172 mol), andbenzene (150 ml.) are stirred 5 hours at 95° C. and 16 hours at 25° C.The benzene is removed to give 2-chloro-α,α ,α-trifluoro-p-tolyl-3-(1-chloroformylethoxy)-4-nitrophenyl ether (33.4 g.92%).

b. 2-Chloro-α,α,α-trifluoro-p-tolyl-3-(1-carbamoylethoxy)-4-nitrophenylether

A solution of2-chloro-α,α,α-trifluoro-p-tolyl-3-(1-chloroformylethoxy)-4-nitrophenylether (4.2 g. 0.01 mol) in ether (50 ml.) is added to an ether solution(200 ml.) saturated with gaseous ammonia at zero temperatures. After 30minutes, water (100 ml.) is added and the ether layer separated. Theaqueous phase is extracted with ether (3 × 200 ml.) and the combinedextracts dried, filtered through activated silica gel (˜20 g.), and thesolvent removed to give 2-chloro-α,α,α-trifluoro-p-tolyl-3-(1-carbamoylethoxy)-4-nitrophenyl ether (2.4 g. 60%)m.p.108°-111° C.

EXAMPLE 55 Preparation of2-Chloro-α,α,α-trifluoro-p-tolyl-3-(3-methyl-1-ethylureido)-4-nitrophenylether

a.2-Chloro-α,α,α-trifluoro-p-tolyl-3-(N-ethylchloroformamido)-4-nitrophenylether

A mixture of 2-chloro-α,α,α-trifluor-p-tolyl-3-ethylamino-4-nitro phenylether (3.6 g. 0.01 mol), phosgene (18.9 g. 0.19 mol), 2,6-lutidine (2.2g. 0.02 mol), and benzene (˜130 ml.) are heated in a pressure bottle 64hours at 90°-95° C. The mixture is cooled, filtered and the solventremoved to give2-chloro-α,α,α-trifluoro-p-tolyl-3-(N-ethylchloroformamido)-4-nitrophenylether.

b.2-Chloro-α,α,α-trifluoro-p-tolyl-3-(3-methyl-1-ethylureido)-4-nitrophenylether

A solution of2-chloro-α,α,α-trifluoro-p-tolyl-3-(N-ethylchloroformamide)-4-nitrophenylether (4.4 g., 0.01 mol), methylamine (3.3 g 0.11 mol) and benzene (˜60ml.) is allowed to stand 25 minutes at zero ° C., filtered, and thesolvent removed. Benzene (˜100 ml.) and hexane (50 ml.) are added andthe solution is washed with water (100 ml.) and aqueous 10% sodiumcarbonate solution (2 × 100 ml.), dried, and the product abosrbed onactivated silica gel (˜25 g.). The product is eluted with a mixture ofbenzene (400 ml.) and methanol (40 ml) the solvents removed and theproduct recrystallized to give2-chloro-α,α,α-trifluoro-p-tolyl-3-(3-methyl-1-ethylureido)-4-nitrophenylether (2.6 g. 62%) m.p. 127.5°-128.5° C.

EXAMPLE 56 Preparation of2,6-Dichloro-α,α,α-trifluoro-p-tolyl-3-ethoxy-4-nitrophenyl ether

a. 3,4-Dichloro-5-nitro-α,α,α -trifluorotoluene

3,4-Dichloro-α,α,α-trifluorotoluene (862 g. 4.0 mols) is added to astirred mixture of concentrated sulfuric acid (4400 g.) and nitric acid(3400 g.) at 35° C. The mixture is stirred 70 minutes at 95° C, andallowed to separate. The oil layer is washed once with water and twicewith 5% sodium carbonate solution, dried, and fractionally distilled togive 3,4-dichloro-5-nitro-α,α,α-trifluorotoluene (188 g. 18%) b.p.115°-118° C./15 mm, 88% pure.

b. 5-Amino-3,4-dichloro-α,α,α -trifluorotoluene

500 ml. of an ethanolic solution containing3,4-dichloro-5-nitro-α,α,α-trifluorotoluene (188 g. 0.72 mol), andplatinum oxide (Adam's catalyst) (0.2 g.) is reduced at room temperaturein a low pressure hydrogenation apparatus to give5-Amino-3,4-dichloro-α,α,α-trifluorotoluene (129.9 g. 78%) b.p. 65°-70°C./1-2 mm.

c. 3,4,5-Trichloro-α,α,α-trifluorotoluene

A solution of sodium nitrite (39 g.) in water (85 ml.) is added over 1hour to a solution of 5-amino-3,4-dichloro-α,α,α-trifluorotoluene (117.5g., 0.51 mol) in 1700 ml. concentrated hydrochloric acid at -6° C. andthe solution stirred for 1 hour then filtered. The filtrate is added toa solution of cuprous chloride (76.5 g.) in concentrated hydrochloricacid (500 ml.) over 5 minutes at 0° to 8° C. and gradually heated to 80°C. over 80 minutes. The reaction mixture is cooled to 35° C. andextracted with hexane (2 × 300 ml.). The extract is washed with water,2% sodium hydroxide solution, dried and distilled to give3,4,5-trichloro-α,α,α-trifluorotoluene (70 g., 55%) b.p. 82°-86° C./10mm, 95% pure.

d. 1,3-Bis(2,6-dichloro-α,α,α-trifluoro-p-tolyloxy)benzene

A mixture of 3,4,5-trichloro-α,α,α-trifluorotoluene (10 g. 0.04 mol),and the dipotassium salt of 1,3-dihydroxybenzene (4 g. 0.021 mol) in 150ml. sulfolane is stirred and heated 70 minutes at ˜120° C. The cooledreaction mixture is diluted with benzene (350 ml.) and washed once withwater (1 l). Hexane (200 ml.) is added, and the solution washed withwater (3 × 500 ml.) dried, filtered through activated silica gel (˜25g.), and the solvents removed. The residual oil is crystallized from amixture of pentane and benzene to give1,3-bis(2,6-dichloro-α,α,α-trifluoro-p-tolyoxy)benzene (5.3 g. 49%) m.p.121°-122° C.

e. 1,3-Bis(2,6-dichloro-α,α,α-trifluoro-p-tolyloxy)-4-nitrobenzene

A cooled mixture of concentrated sulfuric acid (6.5 ml.) and nitric acid(4.4 ml.) is added with stirring to an ice cold solution of1,3-bis(2,6-dichloro-α,α,α-trifluoro-p-tolyoxy)-benzene (11.1 g. 0.021mol) in 1,2-dichlorethane (30 ml.). After 30 minutes at roomtemperature, the phases are allowed to separate and the organic phasewashed twice with water. Benzene (200 ml.) is added and the solutionwashed twice with dilute sodium carbonate solution, dried, filteredthrough activated silica gel (˜25 g.), and the solvents removed. Theresidual crystals are triturated with pentane, filtered, and dried toobtain 1,3-bis(2,6-dichloro-α,α,α-trifluoro-p-tolyloxy)-4-nitrobenzene(9.9 g., 82%) m.p. 137.5°-140.5° C., 90% pure.

f. 2,6-Dichloro-α,α,α-trifluoro-p-tolyl-3-ethoxy-4-nitrophenyl ether

A solution of potassium hydroxide, 86% (1.9 g., 0.029 mol) in ethanol(20 ml.) is added to a solution of 1,3-bis(2,6-dichloro-α,α,α-trifluoro-p-tolyoxy)-4-nitrobenzene (8.0 g., 0.014mol) in p-dioxane (70 ml.) and warmed 1 hour at 50° C. The solution iscooled and benzene (˜250 ml.) is added and crystals of potassium2-nitro-5-(2,6-dichloro-α,α,α-trifluoro-p-tolyloxy)phenoxide (2.9 g.52%) are collected. Treatment with acid yields the free phenol,2,6-dichloro-α,α,α-trifluoro-p-tolyl-3-hydroxy-4-nitrophenyl ether (2.0g. 40%) m.p. 84.5°-86.5° C. This phenol (1.7 g. 0.0046 mol) isreconverted to the potassium salt, dissolved in dimethylformamide (20ml.) and treated with ethyl iodide (1.2 g. 0.0077 mol) 2.5 hours at50°-70° C. The reaction mixture is diluted with benzene (˜100 ml.) andhexane (˜50 ml.), washed with water (3 × 100 ml.), dried, filteredthrough activated silica gel (˜15 g.), and the solvents removed to give2,6-dichloro-α,α,α-trifluoro-p-tolyl-3-ethoxy-4-nitrophenyl ether (0.8g. 44%) m.p. 100.5°-102° C.

From the filtrate of the 2.9 g. of phenoxide there is recovered ethyl2,6-dichloro-α,α,α-trifluoro-p-tolyl ether (3.0 g. 82%) b.p. 78° C./5mm, and an additional amount of the product2,6-dichloro-α,α,α-trifluoro-p-tolyl-3-ethoxy-4-nitrophenyl ether (0.35g. 6%) m.p. 88°-93° C.

EXAMPLES 57 to 72

Following the procedures of Examples 1 to 56, other diphenyl ethers ofFormula I are prepared. Among the compounds which are prepared by theseprocedures are:

α,α,α,α',α',α'-hexafluoro-2,4-xylyl-3-ethoxy-4-nitrophenyl ether

α⁴,α⁴,α⁴ -trifluoro-2,4-xylyl-3-n-propoxy-4-nitrophenyl ether,

2-chloro-6,α,α,α-tetrafluoro-p-tolyl-3-ethyl-4-nitrophenyl ether,

2-iodo-α,α,α-trifluoro-p-tolyl-3-methoxy-4-nitrophenyl ether,

2-chloro-6-cyano-α,α,α-trifluoro-p-tolyl-3-methylthio-4-nitrophenylether,

2-bromo-α,⁴ α, ⁴ α⁴ -trifluoro-4,6-xylyl-3-ethoxy-4-nitrophenyl ether,

2-chloro-α,α,α,α',α',α'-hexafluoro-4,6-xylyl-3-methoxy-4-nitrophenylether,

2-bromo-α,α,α-trifluoro-p-tolyl-3-ethoxy-4-nitrophenyl ether,

2-chloro-α,α,α-trifluoro-p-tolyl-3-n-butyl-4-nitrophenyl ether,

2-chloro-α,α,α-trifluoro-p-tolyl-3-bromo-4-nitrophenyl ether,

2-cyano-α,α,α-trifluoro-p-tolyl-3-acetoxy-4-nitrophenyl ether,

2-bromo-α,α,α-trifluoro-p-tolyl-3-diethylamino-4-nitrophenyl ether,

2,6-dichloro-α,α,α-trifluoro-p-tolyl-3-ethylamino-4-nitrophenyl ether,

2-cyano-α,α,α-trifluoro-p-tolyl-3-(1-carbethoxyethoxy)-4-nitrophenolether,

2-cyano-α,α,α-trifluoro-p-tolyl-3-carbomethoxy-4-nitrophenyl ether, and

2-bromo-α,α,α-trifluoro-p-tolyl-3-carboxy-4-nitrophenyl ether.

These diphenyl ethers have herbicidal properties.

It should be noted that the diphenyl ethers of the invention can also benamed correctly using different systems of nomenclature. For example,the diphenyl ether of Example 3 can also be named as2-cyano-4-trifluoromethyl-3'-ethoxy-4'-nitrodiphenyl ether. However,within the specification and claims of this invention the system ofnomenclature exemplified in Examples 1-56 has been followed.

The following examples show the herbicidal properties of the diphenylethers of the invention.

EXAMPLE 73

This example shows the herbicidal activity of diphenyl ethers of theinvention towards a number of common weeds. Using the proceduredescribed below, diphenyl ethers were evaluated for control of thefollowing weeds:

At 10 pounds per acre:

Monocots

barnyardgrass (Echinochloa crusgalli)

crabgrass (Digitaria spp.)

nutsedge (Cyperus esculentus)

wild oats (Avena fatua)

Dicots

bindween (Convolvulus arvensis)

curly dock (Rumex crispus)

velvetleaf (Abutilon theophrasti)

wild mustard (Brassica haber)

At 2 and 4 pounds per arce:

Monocots

barnyardgrass (Echinochloa crusgalli)

**Bermudagrass (Cynodon dactylon)

crabgrass (Digitaria spp.)

*downy brome (Bromus tectorum)

foxtail (Setaria faberii)

Johnsongrass (Sorghum halepense)

nutsedge (Cyperus esculentus)

quackgrass (Agropyron repens)

*ryegrass (Lolium perenne)

*wild oats (Avena fatua)

*yellow millet (Panicum miliaceum)

Dicots

binweed (Convolvulus arvensis)

cocklebur (Xanthium pensylvanicum)

**coffeeweed (Sesbania macrocarpa)

*curly dock (Rumex crispus)

*lambsquarters (Chenopodium album)

morningglory (Ipomoea purpurea)

*pigweed (Amaranthus retroflexus)

**ragweed (Ambrosia artemisiifolia)

*smartweed (Polygonum pensylvanicum)

**tomato (Lycopersicon esculentum)

velvetleaf (Abutilon theophrasti)

*wild carrot (Daucus carota)

*wild mustard (Brassica haber)

The following test procedures is employed. Seeds of selected crops andweeds are planted in soil in flats. For preemergence tests, the flatsare treated with the test compound immediately after the planting. Forpostemergence tests, the seeds are allowed to germinate, and after 2weeks the flats are treated with the test compound. The compound to beevaluated is dissolved in acetone, diluted with water, and sprayed overthe flats using a carrier volume equivalent to 50 gallons per arce atthe rate of application (pounds per acre, lb/A.) specified in thetables. About 2 weeks after the application of the test compound, thestate of growth of the plants is observed and the phytotoxic effect ofthe compound is evaluated. Table II gives the average percent controlachieved by the test compounds in terms of the percent of the plantswhich are killed by the compounds.

                  TABLE II                                                        ______________________________________                                        HERBICIDAL ACTIVITY                                                           (% control)                                                                   Compound of      Preemergence  Postemergence                                  Example No.                                                                            lb./A.  10     4    2     10   4    2                                ______________________________________                                        1         M*     42     76         82   57                                              D*     35     45         100  58                                    2        M       97     97         100  99                                             D       100    80         100  100                                   3        M       99     89   **84  100  99   +96                                       D       100    99   **66  100  100  +97                              4        M              98              80                                             D              100             100                                   5        M       97     84         100  99                                             D       100    78         100  100                                   6        M       65     77         97   91                                             D       70     55         100  94                                    7        M       61     65   65    100  75   82                                        D       60     57   54    100  77   80                               8        M       81     61   52    85   48   35                                        D       82     57   46    100  80   66                               9        M       99     90   81    100  97   82                                        D       92     66   67    100  81   75                               10       M              70   66         67   17                                        D              100  70         98   85                               11       M              81   88         82   100                                       D              98   99         99   100                              12       M              86   72         77   99                                        D              96   93         100  100                              13       M              76   78         77   100                                       D              90   72         98   100                              14       M              64   30         61   91                                        D              78   22         94   100                              15       M              99   68         79   76                                        D              100  90         99   94                               16       M              86   67         77   82                                        D              94   75         96   94                               17       M              51   20         45   39                                        D              84   31         89   98                               18       M              67   99         28   28                                        D              100  100        86   98                               19       M              91   77         84   94                                        D              96   91         98   97                               20       M              88   80         78   80                                        D              99   93         88   97                               21       M              91   79         74   90                                        D              99   90         96   94                               22       M              72   63         60   70                                        D              98   77         99   100                              23       M              90   55         82   71                                        D              64   87         100  100                              24       M              91   62         86   84                                        D              68   97         99   100                              25       M              87   40         97   88                                        D              88   93         100  100                              26       M              98   75         99   93                                        D              100  99         100  100                              27       M              76   74         82   99                                        D              98   90         100  100                              28       M              74   79         73   73                                        D              95   79         99   100                              29       M              74   66         79   97                                        D              73   84         100  100                              30       M              81   78         75   91                                        D              99   94         100  100                              31       M              74   68         61   68                                        D              99   69         100  100                              32       M              86   81         86   100                                       D              100  81         100  100                              33       M              53   79         32   65                                        D              99   74         98   100                              34       M              35   83         32   47                                        D              52   85         89   90                               35       M              40   60         45   63                                        D              40   72         98   80                               36       M              93   100        87   94                                        D              100  100        100  98                               37       M              99   100        92   100                                       D              100  100        100  100                              38       M              47   62         43   51                                        D              86   68         98   58                               39       M              65   77         64   61                                        D              99   80         98   100                              40       M              86   88         64   81                                        D              92   98         100  100                              41       M              60   84         71   56                                        D              96   62         95   94                               42       M              62   83         38   63                                        D              80   60         98   88                               43       M              0    99         2    61                                        D              48   100        47   80                               44       M              66   0          60   7                                         D              96   17         98   10                               45       M              13   68         17   53                                        D              58   77         88   78                               46       M              0    34         0    0                                         D              20   87         30   4                                47       M              61   80         11   24                                        D              40   80         72   84                               48       M              99   100        75   84                                        D              97   100        100  97                               49       M              92   100        86   77                                                       95   100        100  100                              50       M              90   98         97   100                                       D              83   100        100  100                              51       M              79   96         75   86                                        D              100  100        100  98                               52       M              79   98         87   93                                        D              67   75         100  100                              53       M              98   98         79   81                                        D              83   100        100  100                              54       M              83   98         79   71                                        D              75   98         100  100                              55       M              91              69   31                                        D              73              95   96                               56       M              91   100        99   100                                       D              83   100        100  99                               ______________________________________                                         *M = Monocots: D = Dicots                                                     **1/4  lb./A.                                                                  +1/2  lb./A.                                                            

EXAMPLE 74

This example shows the selective herbicidal activity of diphenyl ethersof the invention in a number of agronomic crops. Following the generaltest procedure of Example 73, diphenyl ethers are evaluted forsignificant tolerance (as shown by 50% or less kill of the test crop atlevels of application which give more than 50% kill of many or all ofthe weeds of Example 73) towards some or all of the following commonagronomic crops (not all compounds tested against all crops): alfalfa,snapbeans, corn, cotton, cucumbers, peanuts, rape, rice, safflower,soybeans, tomatoes, and wheat.

Tolerance to snapbeans in preemergence applications is shown by thecompounds of Examples 4 and 26. Tolerance to corn in preemergenceapplications is shown by the compounds of Examples 4, 11, 19, 21, 34,40, 52, and 54 and in postemergence applications by the compounds ofExamples 4, 18, 19, 21, 26, 34, 36, 40, 52, 53, 54, and 56. Tolerance tocotton in preemergence applications is shown by the compounds ofExamples 3, 4, and 30 and in postemergence of layby applications by thecompound of Example 3. Tolerance to peanuts in preemergence applicationsis shown by the compounds of Examples 3, 19, 21, 30, 34, 36, 40, 48, 49,50, 52, 53, and 56 and in postemergence applications by the compounds ofExamples 4, 18, 34, 36, 37, 40, 48, 53, and 54. Tolerance to rice inpreemergence applications is shown by the compounds of Examples 4, 19,21, 30, 34, 40, 52, and 54 and in postemergence applications or inapplications or transplanted rice by the compounds of Examles 3, 11, 18,20, 30, 34, 40, 48, 53, and 54. Tolerance to safflower in preemergenceapplications is shown by the compound of Example 3. Tolerance tosoybeans in preemergence applications is shown by the compounds ofExamples 3, 4, 11, 18, 19, 21, 26, 30, 34, 40, 48, 49, 50, 52, 53, and54, in postemergence or layby applications by the compounds of Examples3 and 34. Tolerance to wheat in preemergence applications is shown bythe compounds of Example 4, 18, 19, 26, 34, 40, 50, 54, and 56 and inpostemergence applications by the compounds of Examples 4, 18, 21, 30,34, 36, 48, and 54.

It is to be understood that changes and variations may be made withoutdeparting from the spirit and scope of the invention as defined by theappended claims.

We claim:
 1. A compound of the formula ##STR6## wherein X is a cyanogroup,Y is a hydrogen atom, a halogen atom, or a trifluoromethyl group,and Z is a hydroxy group, an alkoxy group having up to 6 carbon atoms,an alkyl group having up to 4 carbon atoms, a halogen atom, an aminogroup, an alkylthio group having up to 4 carbon atoms, a cyano group, acarboxyalkyl group having up to 4 carbon atoms, a carbalkoxyalkyl grouphaving up to 6 carbon atoms, an alkanoyloxy group having up to 4 carbonatoms, or a carbamoyloxy group having up to 6 carbon atoms.
 2. Acompound according to claim 1 wherein Y is a hydrogen atom.
 3. Acompound according to claim 2 wherein Z is an alkoxy group.
 4. Acompound according to claim 3 wherein Z is an unsubstituted (C₁-C₄)alkoxy group.
 5. A compound according to claim 4 wherein Z is anethoxy group.
 6. A compound according to claim 3 wherein Z is a halo-,hydroxy-, alkoxy-, carboxy-, carbalkoxy-, trihalomethyl-, alkenyl-,alkynyl-, amino-, alkylamino-, dialkylamino-, alkylthio-,alkylsulfonyl-, epoxy-, alkylcarbonyl-, or carbamoyl-substituted alkoxygroup.
 7. A compound according to claim 6 wherein Z is acarbalkoxy-substituted alkoxy group.
 8. A compound according to claim 2wherein Z is an amino group.
 9. A compound according to claim 8 whereinZ is an (C₁ -C₄)alkyl-, di(C₁ -C₃)alkyl, carboxy-, carb(C₁ -C₄)-alkoxy,or (C₁ -C₄)carbamoyl-substituted amino group.
 10. A compound accordingto claim 9 wherein Z is a diethylamino group.
 11. A compound accordingto claim 1 wherein Y is a halogen atom.